I am a scientist working in molecular biology. Personally, I love my job; I don't know if I could find another career I would enjoy more. I spend about a third of my time tinkering in the lab, a third reading and writing, and a third bullshitting with colleagues about what experiments would be cool to perform. Perfection.

I think there is a place for bioinformatics, and I think it will only get more important as time goes on. But, IMO, I think its great usefulness will come in meta-analyses, which are often severely lacking. Analyzing the genome (or proteome, or transcriptome, or any other "-ome') of a tumor is a waste of time in some sense, but it might get you paid quicker. But meta-analyses of the volumes of data that are out there I think is what will tell us what it is we're all looking at. There are too much data for anybody to make heads or tails of. Bioinformatics will be very important to disease treatment in the future, but it hasn't really found its sea legs yet.

If I were starting from scratch, I would probably do my graduate work in mathematical biology, because I regret that I don't get to use my math skills in my work as often as I would like. But all in all, the population is getting sicker, so if you're in biomedical research and you have something to contribute, you'll have a job somewhere.